(CNN) -- For most people plunging into the ocean's cold, dark depths without an oxygen tank would be an alarming experience. But for Ahmad Tahilmet and his friends its one of life's greatest pleasures.
They are freedivers -- one of the growing number of young Emiratis who pursue the extreme water sport that is growing in popularity.
Unlike regular divers, freedivers prefer to go under water without oxygen tanks or other bulky equipment.
"It has something to do with the ocean and how much we love to be in it. You have so many ways to discover what's under the water," says Tahilmet.
"Some people go into scuba diving. Freedivers usually have a different approach because the silence.
"You have no bubbles, nothing. All that you can hear is your heartbeat and you get to see things that other people can't see. You know because you are so quiet and calm."
For these young Emiratis, freediving is not just a hobby, but it's a competitive sport. But unlike other forms of competition, freediving requires participants to learn to relax, instead of relying on adrenaline.
Freediving has a long history in the UAE, going back to the old days of pearl diving, a one-time traditional livelihood. Driven by the need to make the living, the pearl divers relied on a weight to drag them to the seabed and a rope to guide them out of water.
But as that profession has disappeared, the practice of freediving has taken its place.
"I know it is not a necessity," says Tahilmet. "Now we do it because we love the ocean."
Freedivers compete for either depth or duration of a breath hold under water. And just like his pearl-diving Emirati forebears, present-day free divers such as Ahmed Khouri may opt to use weights to help them drop faster and deeper.
"Personally I prefer to dive with a neck weight," Khouri says. "It just sits around the neck. It's comfortable because it doesn't really choke you. So you'll be alright."
Yet, experts warn that many freedivers, including those in the UAE, don't have enough proper training or understand its dangers. And they warn accidents could rise as more people take part in the sport.
Adel Ait-Ghezala, a 35-year-old Algerian freediver, went missing on New Year's Day while spearfishing with his friends off the coast of Dubai. His body was found around 10 days later.
Both Tahilmet and Khouri are well aware of the dangers; they lost a friend to freediving, also off the coast of Dubai.
But AIDA, the international freediving governing body, says the sport has a strong safety record, and serious accidents in organized competitions, like the recent one late last year, are quite rare. (In November, champion American freediver Nicholas Mevoli died after he surfaced from a 72-meter dive in a competitive event in the Bahamas.)
For Khouri, the thrill of freediving is like doing another kind of extreme sport.
"The most fun part of the dive is the free fall," he says. "It's like people who do skydiving, they just freefalling. It's just the same. You know I think that's the best sensation you can have because the more you free fall, the deeper you go, the more fun you have."